1. Field of the Invention
The present invention relates to a magnetic field type of sputtering device and its process for manufacturing a superconducting oxide ceramic material film.
2. Description of the Related Art
Recently, superconducting ceramic materials have been attracting a great deal of attention. These materials were first reported by IBM's Zurich Laboratories in the form of Ba-LaCu-O (BALACUO) type high temperature superconducting oxide material. In addition, the YBCO (YBa.sub.2 CuO.sub.6-8) types are also known. However, these types could be prepared only by mixing and firing various types of oxide powders to form tablets, so that even when a Tc onset of 90K was obtained, a sufficiently thin film was not possible. In addition, it was completely unknown that the thin film formed at a lower temperature can have crystal grains uniformly oriented in a direction with reference to the surface portion on which the film is formed (which is hereinafter referred to as the film-forming surface portion).
The critical current density of these superconducting materials with polycrystalline oxide structure in tablets is small. In order to correct this problem it is desired that all the ab surfaces of the crystal grains (also referred to as the C surface, the surface perpendicular to the c axis direction) be mutually oriented.
Furthermore, it is strongly desired that the Tco (temperature at which resistance is zero) of the superconducting oxide material be higher. It is desirable that operation be possible at the temperature of liquid nitrogen (77K) or a higher temperature, and that, in turn, the Tco temperature of 90K or higher be available in the structure of the thin film.
With such an objective in mind, the inventor of the present invention filed Japanese patent application No. 62-75205 on Mar. 27, 1987 covering a "Method for manufacturing a superconducting material" which was a method for manufacturing a superconducting material by applying a magnetic field during a heating process.
The present invention is a further development of the above-mentioned invention.